Power bender



March 10, 1942- s. R. ENBERG ET AL POWER BENDER 4 Sheets-Sheet 1 Filed Sept. 25, 1939 A TTORNE Ys' $0 97 jazz Z6 W2 March 10, 1942. s. RJENBERG ET AL POWER BENDER 4 Sheets-Sheet 2 Filed Sept. 25, 1939 A T ORNE Y5.

March '10, 1942. S R ER ET AL 2,275,619

POWER BENDER Filed Sept. 25, 1939 4 Sheets-Sheet 3 IINVENTOR5. 5230276 7? 131%.:2

March 10,1942. 3 R, ENBERG ET AL 2,275,619

POWER BENDER Filed Sept. 25, 1939 4 Sheets-Sheet 4 r BY 1027; 1/1/4285? Patented Mar. 10, 1942 POWER BENDER Stone R. Enberg, Grosse Pointe, and Roger H. Walsh and Louis C. Scheuring, Detroit, Mich, assignors to Ainsworth Manufacturing Company, Detroit, Mich, a corporation of Michigan Application September 25, 1939, Serial No. 296,358

14 Claims. (01. 153-40) This invention relates to metal bending machines and it has particular relation to a power bender for bending automobile window frames or the like.

One object of the invention is to provide an improved power bender which can be manufactured inexpensively, which is of simple structural design so that it may be maintained in operative condition without difficulty, and which is of such character that it will last a long period of time even though used constantly.

.Another object of the invention is to provide a, machine of the above mentioned character which may be quickly changed to accommodate frame members of different cross-sectional configurations and dimensions.

Another object of the invention is to provide a power bender, such as generally indicated,

which includes collapsible elements for enabling quick removal of the finished frame after it has been bent into substantially annular form.

Another object of the invention is to provide a power bender having an improved wiper block of such character that its contour is altered as it contacts parts of varying contour on the form block of the machine.

reference may be had to the accompanying drawings, wherein:

Figure 1 is a plan view generally illustrating one form of the invention;

Fig. 2 is a side elevational view of the shown by Fig. 1;

Fig. 3 is a detail view of the form upon which machine the metal strip is bent;

Fig. 4 is a cross-sectional view taken substantially along the line 4--4 of Fig. 1;

Fig. 5 is a cross-sectional view taken substantially along the line 5-5 of Fig. 3;

Fig. 6 is an enlarged view showing the metal engaging shoe or block; 7

Fig. 9 is a cross-sectional view taken along the line 99 of Fig. 8, and

Fig. 10 diagrammatically illustrates circuits for operating the fluid and electric motors.

Referring to Figures 1, 2, and 4, a supporting table 10 is provided and this is shown as having corner legs I I, l2, l3, and ll,by means of which the table may be anchored to a floor. A motor l6 anchored to the under side of the table ID has a shaft I! provided with a pulley l8 and this pulley, has driving engagement with an endless link belt IS. The belt is also trained about a second pulley 2| that is keyed to a shaft 22 which in turn is supported in bearings 23 and 24 disposed in openings formed in opposed side walls 25 and 26 of a cup-shape support 2! fastened to the under side of the table Ill by bolts 28. Intermediate its ends, as shown by Fig. 1, the shaft 22 has a worm portion 29 andjthis worm portion meshes with a worm wheel 30.

Now directing attention particularly to Fig. 4, in conjunction with Fig. 2, the worm wheel 30 has a central hub portion 39 which has rotary bearing engagement, by means of a sleeve bearing 40, with a central hub portion 4| of the stationary support 21. The hub portion 39 of the worm wheel 30 has an outwardly directed flange 49 at its upper end that is located within a slightly larger opening 5|] in the table H). A ring 32, secured by screws 53 to the upper end of the hub 4|, projects outwardly into a recess 54 at the upper end of the hub 39 and this construction, in conjunction with the supporting of the lower end of the hub 39 on the support 21, rotatably locates the worm wheel on the latter.

The rotary hub 39 of the worm wheel has a heavy disc 56 secured thereon by means of screws 51 and driving dowel pins 58 and it will be observed that the flange 49 projects slightly above the table [0 and above the ring 52 so that when the disc 56 rotates with the worm wheeL'the disc will not have frictional contact with the table It) and with the ring. The disc 56 has a rim BB projecting upwardly at its center and this rim seats in a recess 6| provided in the under side of a form block 62 that is fastened to the disc 56 by means of screws 64. Drive keys 65 are provided between the screws to avoid driving engagement through the latter. The form block 62 may vary in shape depending upon the shape of the strip to be bent, and, as will be evident from Figures 1 and 3, the block has a shape adapted to form a window frame such as shown by Fig. 8. This frame member is indicated by the numeral '10 and as shown both by Figures outwardly moved.

4 and 9, has a curved portion II and a channel portion 12. The block 62 has its rim portion curved, as indicated at 13, to substantially fit the curved surface 'II of the strip ill but it will be noted in Figs. 3 and 5 that this surface portion of the block is interrupted in the region indicated at M, It might be mentioned in this connection that the block 62 immediately below the surface '13, has an annular groove 13 and this groove is adapted to guide a wiper block, as will be described more fully hereinafter.

On the upper side of the block 62, collapsible plates are provided, as indicated at TI, '58,, and i9, and these, in conjunction with fixed plates 80 and BI, and a clamping plate 8.2, define substantially a complete periphery. It is not necessary that the sectors 89 and 8| be inwardly and outwardly movable, as it has been found satisfactory to merely have the sectors "I'I, I8, and I9 inwardly and outwardly movable and to have the plate 82 of clamping character. The peripheral edge of the several plates is such as to conform to the channel portion I2 .of the window frame to be bent, and additionally, the clamping plate has a surface 83 corresponding to block surface 13.

The plate I! is slidably retained on the block 62 by means of slots 99 and screws 9| threaded into the form block and headed guide elements 92 on the pins which have lower portions sliding in the slots and upper heads overlapping the plate at opposite sides of the slot. A slot 93 is also provided toward the outer edge of the plate and a slot 94 fits slidably in this slot and is retained on the form block by means of threaded pins 95. A pin 93 extending transversely through the slide 94 has rollers 91 and 93011 its opposite ends and these rollers, respectively, are

adapted to ride over wedge elements 99 and H33 secured to the form block, when the plate is Engagement of the rollers with the wedge elements 99 and I99 insures a close fitting engagement of the plate with the form block as the plate reaches the end of its outward movement. however, that the wedge elements 99 and I90 are not essential and the rollers may instead have rolling contact directly with the upper sur-- face of the plate at opposite sides of the slot.

The plates 18 and 79 have similar means for guiding and retaining them on the form block 62 and such means are identified by the same numerals.

Movement of the plates outwardly and inwardly is effected by means of a vertically reciprocable plunger I95, which at its upper end has secured thereto an arm I95 provided with bifurcated portions I91, I98, and I09, respectively, extending over the plates Ti, 18, and I9. The bifurcated portions have pins H3 extending therethrough and such pins extend respectively through slots formed in upright elements III, H2, and II 3 on the respective plates 11, I8, and 19. 7 As shown best by Fig. 4, the upright elements III, H2, and H3 are secured to the respective plates by means of screws I I4, and each slot is angled, as indicated at H5, and terminates at its upper end in a vertical portion H6. From this it will be apparent that when the plunger I95 moves upwardly carrying with it the arm I36, the pins IIll ride upwardly in the slots in. the upright elements and cause the plates,

respectively, to move outwardly to positions shown by the broken lines, and when the pins IIB move into the upper vertical end portions of It might be mentioned,

.rod I 23.

the slots, such plates are positively locked against reverse movement until the plunger again moves downwardly.

The plunger I is Vertically slidable in a central opening in the form block 32 and below the form block and within an enlarged opening II! in disc 56 and within hub 4|, the plunger has slidable, bearing engagement with a bearing sleeve H9. At its lower end, the plunger has a piston-like head I29, which has slidable engagement with the inner surface of the hub 4| and the lower side of this head has a socket I2I which receives a head I22 on a reciprocatory rod I23. The head I22 at its lower side engages a thrust bearing I24 which is held on the lower side of the head I20 by means of a plate I25 secured by screws I25 to the head and from this it will be apparent that the rod I23 may be reciprocated vertically for the purpose of moving the plunger I 05 vertically while still allowing rotation of the plunger I95 with respect to the The rod I23 is threadedly connected at its lower end to a piston rod I29 that in turn is connected to a piston I39 which is reciprocatory in a cylinder I3I that is secured in any suitable'way to support 21.

Now referring to Fig. 3, with the sections TI, 18, and I9 collapsed, the straight end of a strip to be bent is movedalong the outer edge of the stationary section 8| and between the inner end of such edge and a shoulder I21 on the clamping plate 82. This shoulder I311 has the same contour as the outer side of the strip. Now directing attention to Fig. 5 particularly, it will be noted that the clamping plate 82 has a tongue portion I32 which is slidably disposed in a groove I33 in the form block 62 and that this tongue, at its inner end, has a widened portion 34 which is located in a recess I35 at the inner end of the groove I33. A pin I 36 journaled in an opening I31 in the form block has an eccentric portion I38 located in an opening I39 in the plate portion I34 and from this it follows that turning of the pin causes the clamping plate to be moved inwardly and outwardly. At its upper end, the pin is journaled in an opening I49 formed in a cover plate I4I which is secured by screws M2, shown by Fig. 3, to the form block 62. The plate I4I lies flush with the upper surface of the form block 62 and thereby does not interfere with positioning of the plates 19 and 8| on the block. Removal and insertion of the clamping plate may be accomplished by removing the plate 8| and expanding the plate 19, and then the cover plate MI and other parts may be removed and replaced as the case may be.

As will be seen in Fig. 5, the form block is cut away under the clamping plate and the surface 83 on the latter is adapted to fit the strip 10. The grooved portion 16 on the form block continues, however, along the clamping plate and is curved as it joins that part of the block extending along plate 8|.

For holding the metal strip against the plates and against the form block as the form block and plates rotate, a wiper block is employed, as indicated generally by the numeral I50 in Figs. 1, 2, 6, and '7, and this is pivotally mounted on trunnions I5I projecting from the arms of a bifurcated bracket I52, which in turn is fastened to a slide I53. The slide I53 is slidable in guides I54 and I55 fastened to the upper side of the table I0 and is adapted to be moved inwardly and outwardly and to be held in its outermost position by a. fluid cylinder mechanism I56. This mechamsm includes a piston rod I51 connected at its outer end to the slide I53 and a piston, not shown, reciprocatory in a cylinder I58. The cylinder I58 is pivotally connected, as indicated at I60, to a bracket IEI, which is in turn fastened to a U-shaped member I62 secured to the table. The member IE2 is adapted to be adjustably positioned longitudinally of the cylinder axis and in order to effect this result, the table has a series of openings I63 in which bolts I64 selectively may be located. It should be understood now that by introducing fluid under pressure into one end or the other of the cylinder, the slide and hence the wiper block I50 is moved inwardly or outwardly as the case may be and when in its outer position, the block is resiliently maintained against the form block and upper plates thereon owing to the fact that fluid under pressure, such as air, is employed. The resiliency of the fluid at all times will therefore cause the pressure block to tend to follow the periphery of the form block as the latter rotates.

hide mentioned has proven very satisfactory in use in that it provides a substantially solid but softer surface engagement with the metal strip to be bent so as to avoid undesirable friction with and scratching or marring of the strip. A retaining flange I12 prevents the laminations from moving outwardly to the right as seen in Fig. 7, and it will be understood that the laminations are inserted from one end of the slot, that is, from one end as seen in Fig. 6. For hOIdiIlg, the laminations longitudinally in the slot, an end plate I13 is provided which is secured at one end of the block by means of screw I 14, while at the lower side of the laminations, a brass, angular element I15 is employed which has a portion I15 extending laterally of the block and engaging the laminations at the lower end, as seen in Fig. 6. The outwardly disposed leg portion of the angular element I15 constitutes in shape and dimensions a continuation of the laminations Ill and it is maintained in position by means of a metal retainer I11 located in the slot I10 and which is anchored to the block by means of a laterally extending pin I18. The laminations and the element I15 are adapted to engage the strip to be bent and above the laminations, a brass insert I19 is provided for engaging the outer side of the channel portion of the strip. This element I19 is held in a recessed portion I80 of the block by means of pins IBI. The steel plate I82 prevents the laminations from damaging the rubber by contact therewith when such laminations are pressed between the strip being bent and the steel bar I84 and it is to be understood that one or more laminations may be pressed inwardly relative to others and that the resilient rubber and plate I82 act as a spring to return the lamination to normal positions. Thus, the outer edge of the grouped laminations may alter in contour and thus alter itself to better accommodate curved edges of the form block and to generally fit the changing contour of the form block. In this way greater area of contact is had at the bends or curves and a bending action occurs which enables readily obtaining a smooth surface along part H of the strip 10.

of the laminations, and the main purpose of it is to prevent undue wear on the lower side of the laminations as might occur if such laminations engaged the folded over edge of the strip to be bent.

At the lower end of the block, as seen in Fig. 6,

a roller I90 is provided which is mounted on a bracket I9I that is pivoted on a pin I92 on the block. An adjustable set screw I93, adapted to engage a corner I94 of the bracket I9I, limits pivotal swinging of the bracket in a counterclockwise direction, and a spring pressed plunger I95, slidable in an aperture in the block and pressed by spring I96, engages a projection I91 on the bracket [SI and tends to swing the roller in such counterclockwise direction. The roller I 90 is adapted to engage the strip to be bent and to prevent twisting thereof. Also, in conjunction with the wiping part of the block, it tends to hold the block in properposition.

Generally speaking, it should now be understood that when the strip initially is locked by the clamping plate, three operations will occur thereafter before the strip is bent. In the first place, the collapsible plates will be expanded by introducing fluid under pressure into the cylinder I3I below the table. Secondly, the wiper block will be moved outwardly against the strip adjacent the clamped end and will be maintained against the strip by resilient fluid pressure. Thirdly, the electric motor will be operated to rotate the form block so as to cause the strip to be bent around the latter. It will be apparent that the two cylinders will be controlled by suitable valves as will readily be understood by those skilled in the art for first introducing fluid to one end and then the other and it does not seem necessary to illustrate these valves in detail. For controlling the operation of the machine, it is thought that the following sufficiently illustrates the circuit arrangement.

Referring to Fig. 10, a spring return push button type switch 200 when pushed closes circuit 20I, thereby energizing solenoid 202 which closes switch 203 and thus circuit 204. A solenoid coil 205 in circuit 204 maintains the latter closed against the action of spring 206, after button 200 is released. The closing of circuit 204 energizes solenoid 201 and this actuates a reciprocating valve 209 to introduce fluid to the left end of cylinder I56 and to the lower end of cylinder I3I and to exhaust fluid from the opposite ends of the cylinder. When the solenoid is deenergized, a spring within the valve returns it is to its original position, wherein fluid under pressure is introduced to the right end of cylinder I56 and to the upper end of cylinder I3I and is exhausted from the other ends thereof. Pressure and exhaust lines leading to the valve are indicated at 2| 1 and 2I2 respectively. Hence, with circuit 204 closed, the wiper block I50 is moved to the right and the collapsible plates on the form block are expanded. It is desired that the plates expand before the wiper block reaches the form block and this result is accomplished by having different lengths of piston strokes and different size cylinders. Other factors may be employed to govern this sequence as will be understood by those skilled in the art.

When the metal strip is inserted and clamped in position and the wiper block and plates have been moved to operative positions, the operator presses a spring return push button switch 229 which starts the motor It. In the motor circuit, closing of switch 220 closes a switch 22l in circuit 222 and after the button is released the circuit stays closed by reason of solenoid 223.

When the form block has practically completed its rotation, a lug 230 adjustably secured in a dovetailed groove 23| in the disc 56 engages a switch arm of an electric switch 232 and opens the circuit controlling the valves so that fluid under pressure is introduced to the right end of cylinder 56 and upper end of cylinder l3! and is exhausted from the other ends thereof. Thus, the wiper block is withdrawn and the plates are retracted. An instant later a lug 234, also secured in the groove 231 but ofiset vertically and circumferentially from the lug 230, engages a pivotal switch arm of an electric switch 235 to interrupt the motor circuit. Then the clamping means is released and the bent strip is removed.

It is to be noted that the switches 232 and 235 normally are closed and when temporarily opened by the lugs moving thereby, they cause the circuits to be broken temporarily and this disengages the solenoids holding switches closed, which in turn allows the latter to open. Then when switches 232 and 235 return to closed positions, the circuits remain open and are in condition again to be closed by the push button switches. In this connection, it will be understood that the motor before finally stopping will cause lug 23!! to ride past switch 235 and if desired an electric brake may be employed in the motor for stopping it at the right position.

When the wiperblock I50 reaches the clamping plate, it will press the strip against the outer surface of such plate and it is to be observed that the ends of the strip, that is, the clamped end and the end on the outer edge of the clamping plate, may overlap circumferentially to a substantial extent. This is important in that the peripheral contour of the strip before its ends i are welded will more closely correspond to the final form to be obtained. Due allowance being made for spring back of the ends, the arrangement results in the strip being in substantially correct form with the ends nicely positioned for 7 Welding. The welded form is shown by Fig. 8.

It may be observed also that the wiper block I50 will be withdrawn when it is near the end of the clamping plate and due to motor carry over,

the block when returned will engage the succeed ing strip along the plate 8|.

Although only one form of the invention has been described and illustrated in detail, it will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the appended claims.

What is claimed is:

1. In a power bending machine, form means defining substantially an annular edge about which a metal strip may be bent, with the end portions of said edge separated substantially in the plane of the annulus so as to provide in said plane a radially inner end portion and a radially outer end portion, and a clamp for clamping one end of the strip against the radially inner end portion of said edge, the radially outer edge of the clamp constituting the radially oute end portion of the edge.

2. In. a power bending machine, form means defining substantially an annular edge about which a metal strip may be bent, with the end portions of said edge separated substantially in the plane of the annulus so as to provide in said plane a radially inner end portion and a radially outer end portion, a clamp for clamping one end of the strip against the radially inner end portion of said edge, the radially outer edge of the clamp constituting the radially outer'end portion of the edge, and such end portions of the edge being located in circumferentially overlapping relation, whereby the strip is bent into a form having overlapping ends.

3. A power bending machine for bending an elongated metal strip substantially into annular form comprising a form block having a substantially annular edge corresponding to a part of the sectional shape of the metal strip of irregular contour which is to be bent, segmental plates on one side of the block and having edges corresponding to another part of the sectional shape of the metal strip, means rendering certain of the plates movable on the support towards and from the center of the annulus so as to retract the edges of certain plates towards the center of the annulus in order to facilitate removal of the formed or bent strip, and a clamping plate for clamping one end of the strip in position on the support during the bending of the strip.

4. A power bending machine comprising a support, elements on the support and adapted to define a form about which a metal strip may be bent, certain of the elements being movable on the support in order to enlarge and reduce the size of the form, whereby removal of the strip after the bending operation is facilitated, power actuated means for moving the movable elements to enlarge the form at the beginning of the bending operation and to reduce the form at the end of the bending operation, a wiper block for pressing the strip against the form, power actuated means for moving the wiper block at the begin ning of the bending operation to a position where it contacts with the form and for retracting the block at the end of the bending operation, and a single control for eflecting actuation of both of said power means, the parts being so constructed and arranged that the collapsible ele ments are fully expanded before the wiper block contacts the form. V

5. In a power bender, a form block about which a metal strip is to be bent, and a wiper block for pressing the strip against the form, said block comprising laminations slidable one on the other and means for resiliently pressing the laminations towards the form so that the laminations may move relative one to another and so that the edges of the laminations jointly provide a surface which accommodates its contour to the bends in the form.

6. In a power bender, a form block about which a metal strip is to be bent, and a wiper block for pressing the strip against the form, said wiper block comprising laminations of rawhide with the edges defining the wiping surface of the block.

7. In a power bender, a form block about which a metal strip is to be bent, and a wiper block for pressing the strip against the block, said wiper block comprising a plurality of laminations adapted to press against the strip jointly, resilient rubber for pressing the laminations against the block, and a thin steel spring plate between the rubber and the laminations.

8. In a power bender, a form block about which a strip of metal is to be bent, a wiper block having a surface for contacting the strip and for bending it about the form block, and a spring pressed roller on one end of the block for contacting the unbent part of the strip and preventing twisting thereof.

9. In a power bending machine for bending an elongated strip into annular form, a block having a peripheral edge corresponding in section to a sectional part of the metal strip of channeled cross-section which is to be bent longitudinally, plates movable between two positions on the block and having peripheral edges corresponding in section to another sectional part of the strip, means for moving the plates from one position where the edge of the plates and the edge of the block jointly correspond to a section of the strip, to another position where the plate dges are withdrawn from theedge of the block, means for holding the strip atone point on the block, and means for bending the strip about the plates and block.

10. In a power bender, a form about which a metal strip is to be bent, a wiper block for pressing the strip towards the form and comprising a series of wiper elements closely arranged so as to jointly presenta full wiping surface adapted to contact the strip, and means for resiliently urging each element towards the strip engaging position and being of such character that any element may be moved separately of the others, whereby the elements may jointly obtain a large wiping surface contour corresponding to the surface of the form so as to thereby bend the strip into the shape of the form with a large surface engagement.

11. In a power bending machine for longitudinally bending a metal strip into substantially a complete annulus which comprises a support, a plurality of peripherally arranged segments on the support having peripheral edges arranged to support the strip during formation of the annulus, means for clamping the strip on one of the ments may be expanded before the bending operation and then withdrawn inwardly of the formed annulus at the end of the bending operation in order to retract the edge from the annulus and allow ready removal of the latter, and means for automatically efiecting such withdrawal of the movable segments at the completion of the bending operation.

12. In a power bending machine for longitudinally bending a metal strip into substantiallya complete annulus which comprises a support, a plurality of peripherally arranged segments on the support having peripheral edges arranged to support the strip during formation'of the annulus, certain of the segments being stationary and others movably mounted on the support so that certain of the segments may be withdrawn inwardly of the formed annulus, means for clamping the strip on a stationary segment at one point along said peripheral edges, a presser element movable relative to the segments along the periphery of the latter for bending the strip around such edges, and means for effecting such relative movement of the element and the segments.

13. In a power bender, a form block about which a metal strip is to be bent, and a wiper block for pressing the strip against the form, said block comprising closely nested small elements movable relative to each other in the plane of the form, and means for resiliently pressing the elements towards the form so that they may move relative to one another in the plane of the form and accommodate the surface of the block to bends in the form.

14. In a power bender, a form about which a metal strip is to be bent, and a wiper block for pressing the strip towards the form, said block comprising two parts adapted successively to contact the strip, one part comprising closely nested elements movable relative to each other in the plane of the form, and means for resiliently pressing the elements towards the form so that they move relative to one another in the plane of the form, the other part comprising a wiper element in alignment with the nested elements and which is relatively non-movable in the plane of the form.

STONE R. ENBERG. ROGER H. WALSH. LOUIS C. SCHEURING. 

